spec-kitty-spdd-reasons

# spec-kitty-spdd-reasons Drive REASONS Canvas authoring and review for missions that opted in to Structured-Prompt-Driven Development (SPDD) via charter selection. The canvas is a thin, agent-curated reasoning layer that sits next to the spec, plan, and tasks; it is **not** a duplicate system mirror. This skill is documentation for the agent. It assumes the SPDD/REASONS doctrine pack (paradigm, tactics, styleguide, directive, template) has already been shipped under `src/doctrine/` and that activation can be detected via the helper described below. --- ## What this skill does - Detects whether the SPDD/REASONS pack is active for the current project. - Loads mission context: `spec.md`, `plan.md`, `tasks.md`, per-WP prompts, charter context, glossary, research notes, contracts, and relevant code. - Generates or updates `kitty-specs/<mission>/reasons-canvas.md` from the seven-section template fragment. - Compiles per-WP REASONS summaries when an implementer or reviewer asks for one (a focused slice of the canvas scoped to a single work package). - Runs comparison-mode review: traces a diff against the canvas and classifies divergences using the drift taxonomy. ## What this skill does NOT do - It does NOT mirror the code as prose. The canvas references source artifacts; it does not duplicate them. Code remains the source of truth for current behavior. - It does NOT overwrite user-authored mission artifacts. When a canvas section already contains user content...